dishwasher arm would not turn

we removed the cracked pieces and attached the new spray arm. it took some time because the new arm looked different than the old,but we did it.... I was the one to order the parts needed i had never done this before my husband said it was broken and we needed to buy a new dishwasher ( he was less than thrilled about that) so i decided to do this myself and find the parts. my husband was very surprised that i did it.... AND SO WAS I... IF I CAN DO IT YOU CAN DO IT!